In this chapter, we are going to focus in on the role of data collection and analysis in local injury control. Data should serve as the foundation of community injury programs. It should also serve as a compass to direct local injury prevention efforts, as the following example illustrates.

Many years ago in California, a community wanted to address the problem of children drowning or nearly drowning in swimming pools. They developed a very good prevention program targeting four- and five-year olds. But when they finally looked at the data, they realized that the children drowning were toddlers between the ages of 15 and 36 months. So they realized that they needed to go back to the drawing board and revise their intervention to help prevent drownings among these toddlers. This is a good example of what can happen if you do not look at your local data.

Gathering and analyzing data is an important first step toward taking a

systematic approach to injury control and violence prevention. In this session we will explore the kinds of data and data analyses that can be useful to you in identifying and understanding your local injury problems.

Uses of data

Let's look at some common uses for data. Data make it possible for you to identify and understand your injury problem. It also helps you to prioritize among a list of injury problems. Data helps you to determine how big specific problems are. It enables you to note patterns of when and how injuries occur. It also allows you to monitor trends: have the injuries increased or decreased over time? Data can even help you to assess emerging injury issues. Using data to help identify behavioral and environmental risk factors for injuries can assist you in designing, implementing and evaluating effective injury prevention programs. Data provides you with the information you must have to promote behavior change and injury-prevention legislation by educating both the public and policy makers.

Data can also be used to help justify the allocation of scarce resources in injury prevention and control. When there are concerns about relatively mild or rare problems that come up in your day to day work, you can

use data to explain your prevention emphasis on more common or severe causes of injury.

Lastly, data is essential for evaluating the effects of legislation or public policy. To make this point, let's take a closer look at an evaluation of the California motorcycle helmet law that was implemented back in January of 1992: If you look at the first chart on the above slide, you can see that Medicaid payments for hospital treatment dropped 40 percent in the two years following implementation of the law. Charges for hospital treatment, especially for motorcycle related head injuries, dropped by about one half in the first year, and even more in the second year. And finally, you can see that deaths and injuries decreased by almost half over the next four years.

Defining injury problems

Now let's consider how we might use data to help define an injury problem. Data can help you to answer the who, how, where, what and when questions that are so important to selecting a cause of injury to address, a target population, and other issues related to the problem that might be useful in specifying an appropriate intervention.

Perhaps the best way to illustrate this point is to look at some hypothetical data and consider some of the ways that we might use it to help develop injury programs: In this first slide, who is it that is being injured? Is it children? Is it elderly white males? Is it adolescents and young adult females? This slide shows the rate of gunshot injuries by age group and race. You can see that whites are noted in blue, blacks are noted in red and American Indians are noted in green. You can also see that blacks have higher rates in all age groups throughout the continuum of life. But the first thing you might note in this graph is the extraordinarily high rate of gunshot injuries among blacks between the ages of 15 and 24. Looking at who is affected can always assist you in determining your target age group, as well as your target race, gender and community.

Now let's use this next graph to discuss the question of how persons are being injured. Based on these data, can you tell if it is from suicide with firearms? Is it from falling down stairs? The graph shows the

leading methods of injury death by intentionality in a specific community. You can see that traffic injuries result in nearly 3,500 deaths. You can see that firearm injuries produce approximately 2,600 deaths. And you can see that about 60 percent of these firearm deaths result from suicide. Another 35 percent result from homicide. And about five percent result from unintentional or other manner. If you look at the number of falls and poisonings and how they are distributed, you can see that they too primarily result from suicide. The hanging and strangulation deaths also appear to result primarily from suicide. This information supports a determination that suicide is a mechanism of injury worth addressing in this community.

Next, let's look at an example that allows us to consider the question of where injuries are taking place. In this slide, you see where

submersion injuries among children under the age of five are occurring. Fifty percent of these injuries -- drownings and near-drownings -- are occurring in swimming pools. Another 20 percent are occurring in bathtubs and hot tubs. But this picture looks very different if you look at the pie for persons greater than five years of age -- for older children and adults:

Now you can see that swimming pools and hot tubs account for 21 percent of the

submersion injuries in this older age group, and you can see that nearly two-thirds of the injuries among this age group occur in recreational waters -- in lakes, in creeks, in rivers and in ponds. These data suggest that a submersion injury prevention program designed to target young children should be substantially different than one designed to target older children and adults.

What about the circumstances under which injuries occur? Consider this chart, which contains information on fire and flame injuries. You can easily see that flammable liquid is the leading cause of these burn injuries. We could look in more detail at the causes of these flammable liquid exposures and how they resulted in burn injuries. It could be from persons priming carburetors in their vehicles, or from people using gasoline to burn trash or burn their grass. The chart breaks down the causes for residential fires. You can see that heating devices and space heaters were the number one cause, and that cigarettes were a close second. Identifying the most common or most important causes in this manner is an important first step before you can effectively take action to address the problem.

Closer consideration of the severity of an injury problem is another important precursor to taking action. How serious are the injuries we are faced with? How many are fatal? Do they require admission to a hospital or can they be treated in an emergency department? This graph shows gunshot injuries by outcome and treatment status. You can see that 27 percent of the victims died either before they got to the hospital or as they arrived there. Another 3 percent died as inpatients in the hospital. So overall, 30 percent of those wounded by gunshot injuries died. Twenty-seven percent of those wounded were admitted to the hospital and survived, and another 40 percent were treated at the local emergency room and discharged home. This information helps us to evaluate the severity of this cause of injury.

The final question we need to address when we are trying to come to better understand an injury problem is that of when the injuries of concern occur. This graph details

injury deaths by year and intentionality in Oklahoma for the years 1981 to 1995. The red line is unintentional injuries, the green line is suicides and the blue line is homicides. You can see a pretty substantial drop in unintentional injuries in the early 1980s, and might want to find out more about what caused the drop. Could it have been motor vehicle legislation that increased seat belt use or decreased average highway speed? Upon further consideration of this data, you can see that there's not much change in the level of suicide or homicide until you get 1995 and then you can see a 50 percent increase in homicide. This should raise a question in your mind about what could have possibly caused such a sharp increase. In this case, the answer is the 1995 Oklahoma City bombing.